Validate not for number and simbol

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>validate</title>

<style type="text/css">

</style>
<script type="text/javascript">
<!--
function ValidateForm1(theForm)
{
var strFilter = /^[A-Za-zƒŠŒŽšœžŸÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýþÿ \t\r\n\f]*$/;
var chkVal = theForm.Editbox.value;
if (!strFilter.test(chkVal))
{
   alert("Please enter only letter and whitespace characters in the \"Editbox\" field.");
   theForm.Editbox.focus();
   return false;
}
return true;
}
//-->
</script>
</head>
<body>

<form name="Form" method="post" action="" enctype="text/plain" id="Form" onsubmit="return ValidateForm1(this)">

<input type="password" id="Editbox" name="Editbox" value="">
<input type="submit" id="Button1" name="" value="Submit">
</form>
</div>
</body>
</html>